Switch-mode power supplies (SMPS) are power management components in modern electronic devices. They provide, among other things, power efficient and galvanically isolated power to multiple loads. To achieve high power processing efficiency and/or galvanic isolation, conventionally one or more magnetically coupled elements, semiconductor switches and associated gate driver circuits are required.
The magnetically coupled elements often suffer from non-trivial leakage inductance phenomena, which necessitate the need for affordable voltage snubber circuits to control the semiconductor switch peak drain-to-source voltages. Because of the price-sensitive nature of SMPS, the snubber circuits are conventionally limited to the cost-effective passive and power lossy resistor-capacitor-diode (RCD) configurations.
In systems sensitive to power losses and heat generation, the dissipation in lossy components in the form of heat is unsuitable. Thus, recycling of energy using an active clamping configuration within the system provides an opportunity for system form-factor reduction and power efficiency improvement.
Additionally, clamping the maximum drain-source voltages of switching power transistors allows for increased device reliability and use of power transistors with improved figure-of-merit (FOM). The improved FOM enables the SMPS to operate at higher switching frequency while maintaining high power processing efficiency. Furthermore, it allows for a reduction of the SMPS reactive component size and cost.